Isolation of two new bioactive proanthocyanidins from Cistus salvifolius herb extract
作者:Qa'dan, Fadi、Nahrstedt、Schmidt
DOI:10.1691/ph.2011.0839
日期:——
Two new proanthocyanidins, epigallocatechin-3-O-p-hydroxybenzoate-(4β→8)-epigallocatechin (1) and epigallocatechin-3-O-p-hydroxybenzoate-(4β→8)-epigallocatechin-3-O-gallate (2) in addition to the known compound epigallocatechin-(4β→6)-epigallocatechin-3-O-gallate (3), were isolated from the air-dried herb of Cistus salvifolius. The chemical structures were determined on the basis of 1D-and 2D-NMR-spectra (HSQC, HMBC) of their peracetylated derivatives, MALDI-TOF-mass spectra, and by acid-catalysed degradation with phloroglucinol. The isolated compounds 1–3 and the water extract of C. salvifolius herb were tested for their inhibitory activities against COX-1 and COX-2. Compound 2 showed the strongest inhibitory effect on COX-2 followed by compound 3, compound 1 and the water extract, while compounds 1–3 exhibited moderate in vitro inhibition against COX-1.
从风干的岩蔷薇(Cistus salvifolius)草本中分离出两种新的原花色素,表没食子儿茶素-3-O-对羟基苯甲酸酯-(4β→8)-表没食子儿茶素(1)和表没食子儿茶素-3-O-对羟基苯甲酸酯-(4β→8)-表没食子儿茶素-3-O-没食子酸酯(2),以及已知化合物表没食子儿茶素-(4β→6)-表没食子儿茶素-3-O-没食子酸酯(3)。通过其全乙酰化衍生物的1D和2D-NMR光谱(HSQC, HMBC)、MALDI-TOF质谱以及与间苯三酚的酸催化降解,确定了化学结构。对化合物1-3以及岩蔷薇草本的水提取物进行了抑制COX-1和COX-2活性的测试。化合物2显示出最强的COX-2抑制效果,其次是化合物3、化合物1和水提取物,而化合物1-3表现出中等程度的体外抑制COX-1活性。